strange fish and spawn

Question
QUESTION: We have a country pond just under an acre.  We started with 4 koi about 6 or so years ago and they have multiplied a bit, but are not overwhelming.  However, this year we noticed at least 2 doz. of a small (at this stage) black fish with squarish type head, some smalllish fins about 7" in length.  They dart about and seem very busy.  Someone has suggested they may be "bullmouth" or "bullhead".  Do you have any idea?  We would not like to have them in the pond but since we don't know what they are, we certainly don't have any idea how to get rid of them.  Any suggestions?  We thought of introducing largemouth bass to keep the koi population in control, do you think they would also work with these?  Do you then have an explosion of largemouth bass?

The other thing we noticed in the shallow run-off section of the pond is some sort of spawn that we initially took to be pieces of old rope until we looked further and noticed that it was ropes of spawn -- little black things inside a clear gel -- but which look light brown in the water.  Any idea on the spawn?  Was reluctant to destroy in case it was something useful.  Definitely NOT frog spawn.

Many thanks,

Jo

ANSWER: Hi Jo,

In order to give you a better answer I need to know your location.

---------- FOLLOW-UP ----------

QUESTION: Sorry, my location is the western Catskills, NY State.  Perhaps it is toad spawn?

Jo

Answer
Hi Jo,

I think that you should not worry about the fish in your pond.
This is just Nature taking its course, and a healthy environment is full of different creatures.
The rope like thing is probably toad spawn.
You should be happy, because any damage done to the environment, frogs and toads are the first ones to disappear.

Good luck

Carlo